Since its isolation from bulk graphite in 2004, graphene, which is a one-atom-thick sheet of carbon, has attracted an increasing amount of interest. As of this writing, the study of the electronic properties of this two-dimensional (2D) material is one of the most active areas of condensed matter physics. This general endeavor has also stimulated new directions in related research fields, especially those originally inspired by the physics of electronic transport in crystalline solids.
For example, the study of graphene has led to work on photonic materials whose dielectric constants are periodically structured at the subwavelength scale—so-called photonic crystals. By exploiting the analogy between the propagation of electrons in graphene and the propagation of photons in suitably designed 2D photonic crystals, phenomena such as directional optical waveguiding, pseudodiffusive transport of light, Klein tunneling, and the observation of the Zitterbewegung of photons have been recently proposed. However, these 2D photonic crystals share a common fundamental drawback: they lack fully omnidirectional out-of-plane light confinement, which has so far prevented the creation of a truly realistic implementation of a photonic counterpart of graphene.